'''
请实现一个函数，把字符串 s 中的每个空格替换成"%20"。

 

示例 1：

输入：s = "We are happy."
输出："We%20are%20happy."

'''
class Solution:
    def replaceSpace(self, s: str) -> str:
        s = list(s)
        space_count = 0
        for i in range(len(s)):
            if s[i] == " ":
                s[i] = "%20"
        return "".join(s)